First time ordering online, feeling nervous

So i've been buying depends with tabs from the stores for the longest time and walmart removing them from their shelf in my area has forced me to finally purchase my diapers online and decided XP medical would be my best bet price wise. I considered a P.O box but after looking at the prices i felt it was going to cost too much as well as the fact that the boxs you can rent are pretty small and am unsure if they will be able to fix a case. So i'm having to mail them to my house and feeling very paranoid about my mom or brother finding out. my mom kind of already knows but doesnt know i still actively wear diapers. How discreet is XP medical, Do they do tracking numbers so i can be notified when it arrives? Just wanting some reassurance, really nervous that my mom or brother will get to the package first and wonder what i am ordering and google the name on the box.

First time ordering online, feeling nervous